Eyepiece having a wide field of view and a large eye relief

ABSTRACT

An eyepiece having a wide field of view and a large eye relief. The eyepiece is made up, going from the front to the rear, of a double convex singlet, a negative meniscus-shaped doublet concave to the front, a positive meniscus-shaped doublet concave to the front, a double concave singlet, two double convex singlets and a positive meniscus-shaped doublet convex to the front.

uav' v v DH GR 396129662. 7' WK? 1V United States 1 [111 3,612,662

SUbblllUlt l-UH WEEING OR [72] Inventor Harold N-SlIel [56] ReferencesCited Gje g, C OTHER REFERENCES APP! 54301 Winkler Spherizing aSeven-Power, Wide-Field Eyepiece [221 My Design" Applied Optics Vol. 5,NO. 9, Sept. 1966, pages [45] Patented Oct. 12, 1971 [73] Asian xmxc I1371-- 1373. 350/175 (E).

Stamford, Conn. Primary Examiner-John K. Corbin Attorneys-James JRalabate, John E. Beck, Franklyn C.

Weiss and lrving Keschner [$4] EYEPIECE HAVINGAWIDE FIELDOFVIEW AND ALARGE EYE RELIEF 1 2 I ABSTRACT: An eyepiece having a wide field of viewand a [5 2] US. 350/214, large eye relief. The eyepiece is made up,going from the front 350/175 E to the rear, of a double convex singlet,a negative meniscus- [51] hit. G02b 9/64, shaped doublet concave to the,front, a positive meniscus- G02b 25/04 shaped doublet concave to thefront, a double concave singlet, [50] Fleldofseordl 350/214, two doubleconvex singlets and a positive meniscus-shaped [75 E doublet convex tothe front.

EYEPIECE HAVING A WIDE FIELD OF VIEW AND A LARGE EYE RELIEF Thisinvention relates to eyepieces. More particularly, this inventionrelates to an eyepiece that is especially suited for use in night visiondevices or systems but not exclusively limited thereto.

Eyepieces are well known in the art. Examples of eyepieces I can befound in U.S. Pat. No. 2,549,158, US. Pat. No. 2,621.564 and U5. Pat.No. 3,384,434.

it is an object of this invention to provide a new and improvedeyepiece.

it is another object of this invention to provide a high-performanceeyepiece.

it is still another object of this invention to provide an eyepiece thathas a wide field of view and a large eye relief.

it is yet still another object of this invention to provide an eyepiecethat has a large exit pupil.

it is another object of this invention to whose overall length isrelatively short.

it is still another object of this invention to provide an eyepiece thatis inexpensive, is lightweight and has low distortion.

it is yet still another object of this invention to provide an eyepiecethat does not contain any aspheric surfaces.

The above and other objects are achieved by constructing an eyepieceaccording to this invention. Briefly the eyepiece is made up, going fromthe front to the rear, of a double convex singlet, a negativemeniscus-shaped doublet concave to the front, a positive meniscus-shapeddoublet concave to the front, a double concave singlet, two doubleconvex singlets provide an eyepiece and a positive meniscus-shapeddoublet convex to the front.

in the drawings:

FIG. 1 is an optical diagram of an eyepiece constructed according tothis invention; and

F 1G. 2 is a chart of constructional data related to the eyepiece shownin FIG. 1.

Referring to the drawings, there is shown in FIG. 1 an optical diagramof an eyepiece constructed according to this invention. The eyepiece ismade up of seven lens components identified in ascending order byreference numerals I through Vll going from the front to the rear (i.e.,from the left to the right in the drawing).

Component l is a double convex single element A. Component ii is anegative meniscus-shaped doublet concave to the front and is made up ofa negative meniscus-shaped element B concave to the front and a negativemeniscus-shaped element C concave to the front. Component lll is apositive meniscus-shaped doublet concave to the front and is made up ofa double concave element D and a double convex element E. Component IVis a double concave single element F. .Component V is a double convexsingle element 6. Component Vl is made up of double convex singleelement H. Component Vii is a positive meniscus-shaped doublet convex tothe front and is made up of a positive meniscus element 1 convex to thefront and a negative meniscus element J convex to the front.

The exit pupil Dm is in front of the first element A.

The constructional data for one embodiment of the eyepiece is shown inFIG. 2 and repeated in the following table.

in FIG. 2 and in the table the letter N stands for the index ofrefraction, the letter V stands for the Abbe number, the unit for allthe numbers is inches unless otherwise specified, a minus sign in frontof a radius denotes that the surface is concave to the front (i.e.. inthedirection towards the eye) and no sign in front of a radius denotesthat the surface is convex to the front.

Component Element Radii Thickness N V or spacing I {A R1=312.9907

t =0.588 1. II C R.=-0.921s 2 788 4 '5 =0.151 1. R =l.l0G7 I 786 26 l s=0.009 D Rs= 8.9646 2 1; =0.1 1. III E R1==3.53l2 84 m 26 l t =O.720 7R'= L8534 s 1. 88 47 4 Ss=0.094 Iv {F R|= 1.6149 t s v {G R 1=14.0429 4S5=0.m8 VI {H Ru= 2.7428 t R,.= -s.742o

st=0.009 I R1;=1.2912 t 0 .560 1. 788 47. 4 VII R =7.1641

I iim=0.141 1. 785 26. 1

No'rI: E.F.L.=1.0799; F.0.V.=48.98; Overall Length=5.88; Eye n ggbmon;Exit Pupil=0.3937; B.F.L.=0.4l9; Distortion at 2-iA9= ThicknessComponent Element Radii or spacing N V R1=312.9907 I I A t.=o.141 1. 73sI 47. 4

S1=0.342 B Rt= 0.6978 t o 588 2= 1. 788 47. 4 II R|= 0.9278

S:==0.(Il9 D 89646 t 0 154 l 1. 785 26. 1 III R =3.5312 1 E t.=o.720 1.788 47. 4

S3=0.094 Ra= 1.6149 1v F t|=0.189 1. rss I 26. 1

S4=0.08 R 14.0429 v o z,=0.4sa I 1. 788 47. 4

S5=0.008 R13= 2.7428 VI H t =0.660 1. 788 1 47. 4

s =0.009 R15= 1.2912 I tg=0.560 1. 788 47. 4 VII R =7.1641

J t =0.141 1 785 as 1

1. An eyepiece made substantially according to the followingspecifications, wherein the components are designated by Roman numeralsin ascending order from the front to the rear;